Features of the specific, spatial and trophic structure of macrobenthos communities in a lagoon ecosystem located at the outlet of the inner area of the Kislaya Bay (Kandalaksha Gulf, White Sea) were studied. 35 species of benthic invertebrates, as well as 9 ones of seagrasses and algae, were found in the lagoon. In it, there is a well–marked vertical gradient in the macrobenthos community structure (from the upper littoral to the middle, lower, and sublittoral) and a less pronounced longitudinal one, from more silty and desalinated coastal habitats to marine ones. Our statistical analysis made it possible to identify a sublittoral macrobenthos (dominated by Macoma balthica mollusks and polychaetes Terebellides stroemi, Nereimyra punctatata, Pontoporeia femorata, Scoloplos armiger, Phyllodoce maculata ), a community of macrobenthos of the lower and middle littoral, dominated by Macoma balthica, Mya arenaria (more in the middle littoral), Arenicola marina, Littorina littorea and Mytilus edulis (more in the lower littoral) and the macrobenthos community of the upper littoral, together with the inner district middle littoral, dominated by small eurytopic species Peringia ulvae, Tubificoides benedii and Littorina saxatilis . In the lagoon, due to its shallow waters, isolation from the sea, predominance of silt-sand sediments and some freshening, mainly detritiphages predominate; their percentage decreases in the middle and lower littoral and increases towards the sublittoral and upper littoral.
For the first time, information on the taxonomic diversity, distribution features and categories of status of birch mice of the genus Sicista in the Volga region was summarized based on an analysis of our own and literary chromosomal and molecular data, a study of museum collections and regional Red Data Books. The important role of chromosomal and molecular markers in clarifying the taxonomic status of Sicista species and forms and their location in various districts of the Volga region has been confirmed. A gradient was identified in the biodiversity of the genus, represented by sibling species and forms of an unclear taxonomic rank Sicista of the betulina and subtilis groups, generally coinciding with the north-to-south change of the natural zones in the Volga region. Data on the status category of protected species and forms of mice were extracted from the Red Data Books of the Volga regions and the Appendices to them, and the role of protected areas in the Volga region in the preservation of rare species and forms of Sicista was partly shown.
Data on the abundance, biomass, and species composition of planktonic crustaceans, rotifers, and ciliates, as well as the abundance of microorganisms such as bacteria, heterotrophic nanoflagellates, testate amoebae, and phytoplankton pigments were obtained during a three-month study of a small water reservoir where a predatory plant Utricularia vulgaris L. was the dominant species in the phytocenosis. The concentrations of chlorophyll a and the number of bacteria indicated the eutrophic status of the pond. Copepoda (Cyclopoida and Calanoida) accounted for the majority of zooplankton abundance and biomass. Cladocera were represented by two small-sized species Bosmina longirostris (O. F. Müller) and Chydorus sphaericus (O. F. Müller). The highest abundance of rotifers, ciliates, and testate amoebae was observed in early summer. The Utricularia traps studied contained 2–4 organisms. A total of 26 different species and other taxa were identified among the victims. Larvae of Chironomidae, as well as copepodites and adult copepods, were the most common prey items. The number of C. sphaericus in the traps increased during the season. At the same time, the number of C. sphaericus in the plankton population was low. Throughout the entire period of active vegetation, predatory feeding of Utricularia vulgaris was observed, despite some evidence of a high trophic status of the environment and the assumed availability of nutrients for autotrophic nutrition.
The article presents the results of our morphological variation analysis in a few populations of Fritillaria ruthenica Wikstr., F. meleagris L., and F. meleagroides Patrin ex Schult. et Schult. fil., rare ephemeroids of the Liliaceae family. Three populations of F. meleagris , 14 populations of F. ruthenica , and 21 populations of F. meleagroides from the Vladimir, Samara, Penza, Tambov, Voronezh, Saratov, Volgograd, Rostov and Kursk regions, and the Republics of Kalmykia and Bashkortostan were studied in 2014 and 2023–2025. 12 morphological parameters from 30 plants of the generative state were measured in each population. All three Fritillaria species studied are characterized by a high level of intraand interpopulation morphological variability. The contribution of most of the studied morphological traits to variability was statistically significant ( p < 0.05). Plant height and diameter, lower leaf length, width, and thickness, and stem diameter are the most important factors responsible for the observed variation pattern of Fritillaria . As a result of assessing the relationship of the observed variation pattern with environmental variables, the most significant climatic factors were identified. The variation pattern of Fritillaria is virtually independent of altitude. For F. meleagris , a decreasing southwest-to-northeast trend in the parameters most responsible for morphological variation was found across its range. Furthermore, the number of temperature factors correlated with the observed variation pattern was significantly greater than that of humidity factors. In fact, humidity factors significantly influence the pattern of morphological traits variation during the driest period of the year only. For F. ruthenica , unlike F. meleagris , only humidity factors were found to be highly correlated with the variation pattern, and this correlation was moderate, rather than strong, as in F. meleagris . For F. meleagroides , the correlation between bioclimatic factors and the variation pattern was very weak. This is likely due to the fact that, unlike the two previous species, F. meleagroides is a representative of intrazonal vegetation, occupying habitats with high humidity (floodplain meadows) within essentially the same range as F. ruthenica , which grows in steppe areas in regions with the continental climate.
Studies over the last decades have shown that microplastic pollution along with other factors of the anthropogenic impact may have a negative effect on the biological productivity of water bodies, including fluctuations in the numbers and biomass of commercial populations. Due to this ecological problem’s relevance, microplastics were first time surveyed on the Lake Ilmen in May, 2024. The study was carried out throughout the lake, and surface water sampling was made for microplastic particles content using a Manta trawl (335 μm). Analysis of pollutants at 15 stations revealed the presence of synthetic polymer particles, organicand inorganic components, as wel as semi-synthetic fibers in the water samples. This is indicative of the lake micro-scaled pollution, as the found contaminants, including fibers, may pose a potential threat both to single species of aquatic bioresources living in the reservoir and to its ecosystem as a whole. Our quantitative assessment of the concentrations of microplastics and particles of various nature in the Lake Ilmen waters indicates negligible microplastic pollution, not exceeding 0.02 pcs/m 3 . These results can be used as a background (baseline) level for further studies of environmental risk from exposure to microplastics in the Great Lakes of northwestern Russia, which are of commercial fishery importance, as well as in other reservoirs of the Novgorod region.
The paper provides a comparative analysis of mercury (Hg) accumulation in the muscle tissue and organs of commercial fish in the Gor’ky and Cheboksary reservoirs. The research material consisted of 120 specimens of four fish species, namely: Blicca bjoerkna , Abramis brama , Rutilus rutilus , and Perca fluviatilis . The mercury concentrations in the muscles, liver, gills, and gonads were analyzed for each species group. The results showed a pronounced species specificity of accumulation, namely: the highest Hg concentrations were recorded in the muscle tissue and liver, the lowest it in the gills and gonads. Predatory perch is characterized by a higher mercury level, which reflects the influence of its trophic position. Correlation and covariance analysis revealed a significant dependence of mercury concentration in muscles on body length in most fish species, whereas this dependence was less pronounced and variable for the liver, gills, and gonads. The data obtained confirm the informative value of muscle tissue as an indicator of long-term mercury pollution and emphasize the need to take into account the species composition and size-age structure in the environmental monitoring of reservoirs.
Peculiarities of the hydrochemical conditions in the Ivankovskoye, Shushpanskoye, Chelnavskoye, Matyrskoye, Starooskolskoye, Belgorodskoye reservoirs and the biological status of common roach according to our data collected from May to October, 2010–2022, are shown. The study notes that short-term excesses of the limit concentrations of the regulatory values (O 2 , pH, nitrates, ammonia, total iron and phosphates) are not critical for roach growth. E.g., the organic pollution (BOD 5 ) characteristic in the Belgorod reservoir exceeded the norm 4 times. The optimum situation for roach life activity was observed in the Shushpanskoye reservoir, where males reach the largest size of 25.1±0.6 cm and 224.0±17.1 g, females 23.6±0.6 cm and 226.8±11.6 g, respectively. Common roach is able to tolerate short-term excesses of BOD 5 , so roach growth was similar to the average in almost all limnic reservoirs when BOD 5 changed from 1.5±0.2 to 3.4±0.7 mgO 2 /dm 3 . Exceeding BOD 5 by a factor of 4 inhibited the size and weight growth of males and females by a factor of 1.4 on average.
The hemoparasite invasion and immunophysiological status were estimated in 63 marsh frog Pelophylax ridibundus (Pallas, 1771) individuals in three water bodies in the Middle Volga region. Hydrochemical analysis of aquatic habitat of the frogs revealed exceeding of maximum permissible concentrations (MPC) by the content of manganese, copper, chromium, zinc, and cobalt compounds for fishery water bodies. According to the results of the calculation of the specific combinatorial water pollution index (SCWPI), the water quality class of the studied water bodies corresponded to the class 4 (very polluted) and class 5 (extremely polluted). A high infestation with P. ridibundus hemoparasites (58.7
Analysis of the growth characteristics of individuals and the parameters of the anchovy population living on the south-western shelf of the Crimea under conditions of sea surface temperature (SST) changes in 2000–2020 has been performed. The material for our research was the catches of anchovy by trawls on few fishing vessels on the southwestern shelf of the Crimea during the wintering period (November–March). Linear SST trends on the southwestern shelf of the Crimea were estimated. The average annual SST increase in 2000–2020 was 0.055°C. It is shown that the 20-year period can be roughly divided into three periods according to the nature of SST changes, namely: 2000–2007 (I period), 2008–2013 (II period), and 2014–2020 (III period) according to the SST change rate inside each of them. In the warmest period (2014–2020), compared with 2000–2007, the average length of the anchovy increased by 5
During route surveys, habitats of Heracleum mantegazzianum Sommier Levier were identified in the Karachaevo-Cherkessk Republic and Krasnodarsky Krai. Analysis of climatic data showed that within its native range in the Western Caucasus, the optimal conditions for the growth and development of this species occur at elevations ranging from 700 m to 1300 m above sea level. The limiting factors for its dispersal are the duration of the period with stable snow cover and snow depth, which determine the possibility of seed stratification and the risk of cold damage to overwintering plant organs. In its natural habitats in the Caucasus, plants occur singly or in groups of up to 30–50 individuals. In disturbed habitats, the species forms monodominant stands with foliage projective cover close to 100 https://ib.komisc.ru/add/herbarium ).
The protection of soils from pollution and restoration of their natural functions are among the most important problems of sustainable development. At present, scientists from different countries are conducting active studies aimed at searching for the best technologies for remediation of polluted territories. In this regard, bioremediation technologies that involve the use of various microorganisms (MO) (particularly, bacteria) to destroy or inactivate the pollutants can become promising. Bacteria have a quite flexible genetic apparatus. Due to the mutation process, new genes appear in the genome of these MO that allow them not only to survive in the polluted environment, but also to utilize xenobiotics for generating energy and plastic substances. Bacteria belonging to the types Firmicutes, Proteobacteria, Actinobacteria, and Cyanobacteria can be of a particular interest as bioremediation agents. The effective strains of these bacteria are capable of inactivating heavy metals and destroying petroleum hydrocarbons, aromatic compounds, pesticides, pharmaceuticals, dyes, synthetic polymers, and other pollutants. The metabolic capabilities of bacteria can be expanded and enhanced due to editing their genomes and creating artificial self-regulating consortia that comprise symbiotic MO realizing different metabolic pathways. Insufficient stability and viability of the strains, grown in bioreactors, in the natural environment is a serious obstacle to a widespread introduction of bioremediation technologies into practice. The use of latest advances in genetic and cellular engineering, intelligent materials, possibilities of targeted delivery of destructor microorganisms, and intelligent monitoring can contribute to an increase in the stability and efficiency of microbial technologies.
This article presents the temporal organization of springtail communities in tundra ecosystems across European Russia. These ecosystems share similar climatic conditions but vary in vegetation type, permafrost depth, and soil temperature. Our study included both pristine tundra and secondary biocenoses formed due to agricultural activities in the North. In the small-bush and dwarf shrub tundra, the springtail population structure remains relatively stable. This stability is indicative of long-term maintenance of the phytocenosis composition and structure, allowing us to characterize these springtail communities as structurally stable. However, in less favorable environments, such as the large-bush and cold moss-lichen tundra, the springtail communities exhibit slight fluctuations. These fluctuations are marked by an extended set of the dominant species that replace each other over time. In contrast, highly fluctuating springtail communities are characteristic of secondary biocenoses.
The article presents the results of our study on the dynamics of a forest ecosystem type extremely rare in the central Volga Upland, namely, wet sudubrava (C4). The study was conducted in the Upper Sura section of the State Nature Reserve “Privolzhskaya Lesostep”. The process was examined in an age series identified in homogeneous forest growth conditions based on the principles of dynamic classification of forest types. Forest inventory data were processed to obtain average values of forest stand taxonomy indicators for each age class. Changes in all stand components were analyzed simultaneously. Based on this analysis, the age series was divided into individual periods and phases. Trends in the share of each forest-forming species in the stand composition at different age stages are described by nonlinear equations. It is shown that the resulting age series represents a transformation series of forest communities. Disruption of the forest formation process led to a large-scale replacement of native stands with derivatives. After the introduction of clear-cutting, the area occupied by deciduous trees steadily increased. The large-scale use of intermediate, sanitary, and voluntary selective logging resulted in the formation of thinned pine stands. Concurrently, the lower layers of communities were transformed. These factors worsened the conditions for natural regeneration of pine (Pinus sylvestris L.). As a result, the formation of pine stands through natural regeneration is now greatly hampered.
The results of our analysis of the genetic structure of the steppe marmot population restored on the territory of the State Nature Reserve “Privolzhskaya Lesostep” are presented in comparison with its maternal populations for 4 microsatellite DNA loci (Xmoh C10, Xmoh D116, IGS-bp, Ssu17). Some features have been identified that indicate both the quality of the emerging composition of its population and the degree of its stability. According to the allelic spectrum of microsatellite DNA, the introduced population in the reserve is characterized by a high proportion of unique alleles, with a high level of polymorphism of its genetic structure (Hobs—0.775, AGD—0.739), indicating its stable state and no nature selection. The detection of microsatellite DNA alleles not identified in the maternal populations is probably associated with the first (2014) wave of introduced animals, who successfully entrenched in their new habitat and formed the core of the future population. This conclusion is supported by data on genetic distances (Δμ2) and fixation indices (FST) of the five analyzed steppe marmot populations. The highest values of FST were obtained for the population in the reserve in comparison with other populations (0.336–0.301). Similar results were obtained for genetic distances (Δμ2). The highest distance was obtained for two geographically close populations (3.135, 1.564). Thus, the introduced population in the reserve is characterized by a specific genetic structure, which was formed as a result of multi-stage (2014, 2020, and 2021) introduction and stable isolation. The unique features of the genetic structure of the population restored in the reserve are a consequence of the artificial method of its formation. These features stand out clearly against the backdrop of poorly differentiated maternal populations of steppe marmots, which were formed through natural, dynamic population processes.
For the first time, an individual of an extremely rare species of the cladoceran Graptoleberis smirnovi Sinev, Gavrilko, 2020 was found in the Volga–Akhtuba floodplain. The species was found in the summer in the littoral part of the Bolshoy floodplain lake, which is characterized by a high degree of overgrowth with aquatic macrophytes (70 %), high transparency (1.5 m), and water temperature (28 ºC). The abundance and biomass of Graptoleberis smirnovi were 0.5 thousand ind./m 3 and 4.5 mg/m 3 , respectively, which accounted for 0.7 % and 1.1 % of the total abundance and biomass of the community. The size of females ranged from 420 to 550 μm.
The aim of this review is to summarize current knowledge on the factors influencing the toxigenicity of cyanobacteria of the genus Microcystis and their ability to synthesize hepatotoxic peptides known as microcystins. Environmental factors affecting the ratio of toxigenic to nontoxigenic strains in aquatic ecosystems, as well as the expression levels of genes responsible for microcystin biosynthesis, are analyzed. Particular attention is given to the roles of temperature, light intensity, eutrophication, oxidative stress, and the availability of trace elements. Methods for monitoring toxigenic populations, including molecular biological approaches such as PCR and RT-PCR, are also discussed. Understanding the environmental drivers of toxigenic Microcystis proliferation may contribute to predicting the occurrence of microcystins in drinking water sources and determining optimal sampling periods for toxin monitoring in source waters.
In our previous study (Belenkova et al., 2025), we investigated the accumulation of heavy metals in the organs and tissues of striped field mice in the spring. The available literature data on the seasonal features of the accumulation of heavy metals in animal body are contradictory. We repeated our study using samples of striped field mice captured in the fall and compared the obtained data with the spring ones. It was shown that, overall, heavy metal (especially Pb) concentrations in the spring exceeded their fall levels. However, the patterns of heavy metal accumulation in the tissues of animals in specific parks remained the same, namely: the Filevsky Park remained the most polluted, while the Ostankinsky Park remained the cleanest. These results could potentially be used to develop test systems for comprehensive assessments of the ecological state of urban ecosystems, taking into account the seasonal and spatial dynamics of heavy metal circulation in the environment and in the body of free-living species.
The characteristics of the biodiversity of opisthorchids and the infestation of additional hosts in various aquatic ecosystems in a metropolitan area (Novosibirsk city) are presented. The objectives of this study included determining the species composition of opisthorchids metacercariae, analyzing their occurrence and abundance in fish in each of the three groups water bodies, namely: the Ob River, its tributaries, and Berdsk Bay, located within the boundaries of Novosibirsk city and differing in the set of abiotic and biotic characteristics. The composition of the metacercariae hemipopulation in the surveyed water bodies was identical, being represented by three species, namely, Opisthorchis felineus (Rivolta, 1884), Metorchis bilis (Braun, 1890), and Metorchis xanthosomus (Creplin, 1846). However, the infestation of an additional host by opisthorchid larvae of individual species in different water localities was variable and was determined by local environmental features. The most common opisthorchid species in fish caught in the Ob River and Berdsk Bay is O. felineus, the subdominant ones are M. bilis and M. xanthosomus, respectively. In Berdsk Bay small local fish were most frequently and intensively infected with O. felineus (ide, gudgeon, and dace) and M. bilis (ide, gudgeon), while in the Ob River, O. felineus and M. xanthosomus metacercariae were more often recorded in commercial ide. In the additional host inhabiting the Ob tributaries, unlike other water bodies, M. bilis and O. felineus were dominant, with M. bilis metacercariae more often detected in small local fish, gudgeon and ide, and O. felineus, in small-sized roach. Our analysis of the diversity of opisthorchid metacercariae representatives using biological indices indicates a simplified structure of opisthorchid communities in each water body. The most complex structure of the opisthorchid hemipopulation was found in the Ob tributaries (H = 1.01), then in Berdsk Bay (H = 0.51) and in the Ob River (H = 0.32). The highest values of dominance indices (D) are characteristic of the main channel of the Ob and Berdsk Bay, which indicates the abundance of one species of opisthorchid, namely, O. felineus. Low values of the Simpson index in the Ob tributaries indicate the uniformity of the abundance of metacercariae and the absence of obvious dominance of any species.
A revision of the species richness was conducted for the four vertebrate classes (mammals, birds, reptiles, and amphibians) within the territory of Russia. The regional-level biome was set as the territorial unit. An increase in species richness southwards is characteristic for all classes, with specific differences for each class reflected on originally developed maps. The zones of high diversity partially overlap; however, the biomes with the maximum values do not coincide. For mammals, these are the Black Sea–Ciscaucasian (113 species) and the Zavolzhskii–Kulunda (114 species) steppe biomes. For birds, these are the Sayan–Southern Transbaikal (262 species) and the Altai–Sayan (275 species) orobiomes. For reptiles, these are the Dagestan orobiome (31 species) and the Caspian desert–steppe biome (37 species). For amphibians, this is the Dnieper–Volga biome, which includes Kaliningrad oblast (13 species).
